The primary goal of this K23 proposal is to train the Jason J. Nichols, OD MS is an independent clinician-scientist. To achieve this goal, a five-year training program is proposed which emphasizes mentoring and formal coursework in 1) vision science leading to a PhD from The Ohio State University College of Optometry and in 2) biostatistics and epidemiology leading to an MPH degree from The Ohio State University College of Medicine and Public Health. In 1995, the National Eye Institute (NEI) sponsored dry eye workshop report identified contact lens-related dry eye as a major sub-classification of dry eye syndrome. Yet, there has been little clinical research sponsored by the NEI to study the etiology or epidemiology of contact lens-related dry eyes since that time. The proposed training will provide Dr. Nichols with the necessary patient-oriented research skills to conduct an epidemiologic study of contact lens-related dry eye, which has been carefully designed to complement and enhance those skills obtained during the development period. Contact lens-related dry eye may severely impact ocular health by leading to desiccation of the corneal epithelium or an increased incidence of infectious disease. The relation between contact lens dehydration and evaporative changes in the tear film needs to be understood as they may be the primary cause of contact lens-related dry eye. A cross-sectional/nested case-control study will be conducted and the analyses will address risk factors thought to be associated with contact lens-related dry eye. In the cross-sectional phase of the study (Phase I), we will characterize and elucidate the functional significance of the discrepancy between the frequency and severity of dry eye symptoms during contact lens wear. In the nested case-control phase of the study (Phase II), we will test the hypothesis that evaporative factors including contact lens characteristics, tear film changes, Meibomian gland disease, and blanking patterns are associated with an increased risk for contact lens-related dry eye. The long-term objective of this research is to contribute to a better understanding of the etiology and risk factors for contact lens-related dry eye so that progress can be made toward its prevention.